Circuit controlling device



Dec; 27, 1938. A STADLER 2,141,772

CIRCUIT CONTROLLING DEVICE Filed June 30, 1937 f//// five]??? dawfirzazzldzr Patented Dec. 27, 1938 UNITED STATES PATENT OFFICE 2,141,772 CIRCUIT CONTROLLING DEVICE Albert Stadler, Rockford, 111., asslgnor to Garnet W. McKee, Rockford, 111.

Application June 30, 1937, Serial No. 151,154 2 Claims. (01. 200-80).

The present invention relates generallyto deby the latter when the governor is operative, vices for controlling electric circuits. More parthat is, when the weight type elements are flung ticularly the'invention relates to that type of outwards against the force of the compression circuit controlling device which comprises a springs as the result of the governor driving shaft 5 switch for the circuit and a shaft driven governor being driven at or above the predetermined speed. 5 which operates so to control the switch that the Other objects of the invention and the various switch is shifted into one of its positions when advantagesand characteristics of the present the shaft reaches a predetermined speed and is circuit controlling device will be apparent from shifted into its other position when the shaft is a consideration of the following detailed descripdriven at a lower speed or drive of the shaft is tion. 10 stopped. The invention consists in the several novel fea- One object of the invention is to provide a tures which are hereinafter set forth and are circuit controlling device of this type which is more particularly defined by claims at the consimpler in design andmore efficient in operation clusion hereof. l

than previously designed devices of the same gen- In the drawing which accompanies and forms 15 eral character. a part of this specification or disclosure and in Another object of the invention is to provide a which like numerals of reference denote correcircuit controlling device of the type and charsponding parts throughout the several views:

acter under consideration in which the governor Figure l is a plan view of a circuit controlling comprises a cylindrical or disk-like housing on device embodying the-invention; 20 the shaft and an axially shiftable switch actuat- Figure 2 is a vertical longitudinal sectional ing shaft in the central portion of the housing view showing in detail the arrangement and deand also comprises a group or set of ball type sign of the governor and switch and the manner weights which are mounted in radial guide-ways in which the actuating shaft of the governor in the housingfor movement to and from the serves to hold the switch in one of its circuit 25 switch actuating shaft and have applied to the controlling positions when the governor and govouter portions thereof compression springs which ernor driving shaft are at rest or driven at a when the governor driving shaft drops below its speed less than the predetermined speed; and predetermined speed are adapted to overcome Figure 3 is a vertical transverse sectional view outward thrust of the weights resulting from taken on the line 3-4; of Figure 2 andillustrat- 30 centrifugal force and force the weights inwards ing the manner in which the ball type weights against a tapered member on the switch actuatcoact with the tapered member on the switch ing shaft in such manner as to cause the weights actuating shaft to shift the latter axially in one to coact with said member and shift the last direction as the result of inward shift of the mentioned shaft axially in one direction for weights by the compression springs. 35 switch actuating purposes. The device which is shown in the drawing con- A further object of the invention is to provide stitutes the preferred embodiment of the invena circuit controlling device of the last mentioned tion and is adapted for use in controlling a circharacter in which the governor embodies a comcuit consisting of a pair of conductors C and C paratively light spring for shifting the switch It is shown in connection with an electric motor 40 actuating shaft axially in the opposite direction M having an armature shaft m and comprises a for switch actuating purposes when the ball type switch 4 and a governor 5. The governor is fixed weights are flung outwards away from the tato rotate with the armature shaft m of the elecpered member as the result of sufficient centrifutrio motor and operates, as hereinafter de- 4 gal force to overcome the pressure of the comscribed, so to control the switch that the switch pression springs in the outer portions of the is shifted into one of its positions when the arguide-ways in the housing. mature shaft reaches a predetermined speed and A still further object of the invention is to is shifted into its other position when the shaft provide a circuit controlling device which is genis driven at a lower speed or drive of the shaft is eraliy of new and improved construction and in stopped. 50 which the switch is so arranged and constructed The switch .4 is connected to and forms a part that it assumes automatically one of its positions of the circuit consisting of the conductors C and in response to axial shift of the actuating shaft C and comprises as the main parts thereof a by the action of the light spring and is not entube 6, a U-shaped bracket '1, and a tube holder gaged bythe actuating shaft or subject to wear 8. The tube is formed of glass or like material. 55

It is partially filled with mercury or like fluid type conductor material and embodies contacts 9 and ID in the end walls thereof. The conductors C and C are connected respectively to these contacts 9 and ID. The tube 6 is positioned substantially horizontally and is supported by the holder 8 for vertical tilting movement. When the tube is tilted in one direction, as shown in dotted lines in Figure 2, the mercury contacts with both contacts 8 and I0 and forms an electrical connection between the conductors C and C whereby the circuit in which the latter are included is completed. When the tube is tilted in the opposite direction, as shown by full lines in Figure 2, the mercury flows to one end of the tube and breaks the electrical connection between the two contacts. When the-mercury bridges the two contacts the switch is in its closed position and when the tube is tilted so that the mercury is at one end of the tube and does not form an electrical connection between the two contacts the switch is in its open position. The bracket 1 is mounted on a base I l .onwhich the motor M is supported. It is located next to the governor 5 and consists of a cross-wall l2 and a pair of upwardly extending laterally spaced side walls l3. The cross-wall fits against a plate 14 which overlies the top face of, and is secured by-screws or other attaching devices to, the base H. The side walls 13 are arranged in parallel relation and extend in the direction of the armature shaft 122 of the motor M. The holder 8 is in the form of an elongated block of metal and fits between the upper ends of the side walls of the bracket. One end of the holder is pivotally supported by a pin I5 and the other end of the holder embodies an upstanding U-shaped clip IS. The latter is fixedly secured to the holder by means of a screw l1 and grips yieldingly the side wall of the mercury filled tube 6. The pin l5 extends between and is carried by the upper ends of the side walls I3 of the bracket and passes through a cylindrical hole l8 in the tube supporting holder 8. It extends horizontally and so pivotally supports the holder that the latter together with the mercury filled tube is free to tilt or swing vertically. Vertical tilting of the holder and tube is limited by means of an arm l9 and a pair of stops 20 and 2|. The arm I9 is fixed to and depends from the end of the holder which is pivotally supported by the pin l5. The stops 20 and 2| are in the form of pins and extend between and are secured to the side walls l3 of the bracket 1. They are arranged in straddled relation with the lower end of the arm l9 and coact with the latter to limit swinging or tilting movement of the holder and tube. The holder 8 because it is pivotally supported at one end tends to swing downwards in response to the action of gravity. The tube is so arranged with respect to the holder that when the holder swings downwards by gravity the mercury bridges the contacts 3 and I0 and effects closing of the switch. The stop 20 coacts with the arm Hi to limit downward swinging of the holder and tube and is so ar ranged that when the arm strikes against it, it arrests the holder in the proper angular positions for closing of the switch. The stop 2| coacts with the arm I!) to limit upward swinging movement of the holder and tube and is so arranged that it arrests the holder and tube after the latter have been tilted upwards into a position wherein the mercury is at one end of the tube and the switch is thus in its open position. The action of gravity on the holder and tube serves to shift the switch into its normal or closed position and to retain the switch in such position. When the arm I! is swung towards the stop 2| the holder and tube swing upwards and effect closing of the switch. When the arm is released the holder and tube swing downwards until the arm [9 strikes against and is arrested by the stop 20 and the switch is thus in its closed position.

The governor 5 is disposed between the motor M and the switch I and comprises as the main elements thereof a cylindrical or disk-like housing 22, a switch actuating shaft 23, and a pair of ball type weights 24. The housing 5 embodies a centrally disposed laterally projecting elongated hub 25 and has .a central axially extending bore 26 and a pair of guide-ways 21. The hub 25 is formed integrally with the housing and embodies a centrally. disposed socket 28 through which extends the projecting end of the armature shaft m. A set screw 23 extends transversely through the hub and serves to secure the housing for conjoint rotation with the armature shaft. The bore 26 communicates with and is coaxial with the socket 28 and extends through the end face of the housing which faces the bracket 1 of the switch. It is larger in diameter than the socket and is closed as far as its outer end is concerned by an end cap 30. The latter is removably secured in place by means of a screw thread connection 3| and embodies a cross-wall 32 and a socket 33. The guide-ways 21 communicate withand extend radially from the bore 26 and have the ball-type weights 24 mounted therein for sliding movement to and from the shaft 23. The outer ends of the guide-ways extend through the periphery of the housing 22 and are closed by a pair of plugs 34. The latter, as shown in Figure 2 of the drawing, are secured in place by means of screw thread connections 35 and have comparatively deep diametrically extending kerfs 36 whereby they may be turned by a screw driver or like tool into and out of their operative position or adjusted longitudinally of the guide-ways. Cotter pins 31 extend through aligned holes in the peripheral or outer marginal portion of the housing and the kerfs 36 in the plugs and serve to lock the plugs in place. When it is desired to remove the plugs the cotter pins are removed from the governor housing by pulling them axially through the holes. Thereafter by way of a screw driver the plugs are turned or rotated until they are free from the housing. In the event that it is desired to adjust the plugs axially the cotter pins are removed and then theplugs are turned in the desired direction.

The switch actuating shaft 23 is coaxially positioned with respect to the armature shaft m of the electric motor M. It extends across the central portion of the bore 26 and embodies an integral tapered element 33. One end of the switch actuating shaft fits in an elongated bore 39 in the end of the armature shaft which extends through and fits in the socket 23 in the hub 25 and the other end of said shaft extends through a hole 40 in the cross-wall 32 of the cap 3!. The bore 39 and the hole 40 support the switch actuating shaft so that it is slidable axially. The end of the shaft 23 which extends through the hole in the cross-wall of'the cap 30 is aligned with the depending arm I! of the switch holder 3 and is adapted when said shaft 23 is shifted away from the armature shaft to engage the arm I! and swing the holder and tube upwards into their switch opening position. When the shaft 23 is 75 permits the holder and tube to swing downwards The periphery of the member 38 is curved correspondingly to the periphery of the weights 24 by gravity into their so-called switch closed position. The tapered member 38 is disposed in the bore 28 and'is arranged so that the large end thereof faces the cap 38 and its small end faces the inner end of the socket 28 of the hub 25.

and coacts with said weights in such manner that when the weights are shifted inwards against the member 38 the shaft 23 is shifted away from the armature shaft and effects closing of the switch 4. A light compression spring 4| serves to shift the shaft 23 towards the armature shaft for switch opening purposes when the weights 24 are flung outwards by centrifugal force toward the outer ends of the guide-ways 21. This spring is disposed in the socket 38 in the cap 38 and surrounds the shaft 23. One end of the spring abuts against the cross-wall 32 of the cap and the other end of the spring abuts against the large end of the tapered member 38. The ball type weights 24 are adapted to move outwards in the guide-ways in response to the action of centrifugal force when the governor is rotated. They are slightly smaller in diameter than the guideways and are urged inwards toward the tapered member 38 by way of a. pair of compression springs 42. These sp ngs are of the coil variety and extend between the outer portions of the weights 24 and the plugs 34. The outer ends of the springs are confined in sockets 43 in the inner portions of the plugs. The springs 42 are stronger than the spring 4| and hence when the armature shaft m is at rest or its speed is so slow that outward thrust of theballs due to centrifugal force is overcome, said springs 42 force the weights inwards against the action of the spring 4| and cause the shaft 23 to move towards the bracket 1 and close the switch 4. of the armature shaft m is such that the weights 24 in response to centrifugal force move out wards in the guide-ways against the force of the compression springs 42 the tapered member 38 becomes free with the result that the light compression spring 4| operates to shift the shaft 40 towards thearmature shaft and thus effects closing of the switch. The stop 20 is so arranged and the shaft 23 is of such length that when the shaft is shifted towards the armature shaft by the action of the spring 4| there is no contact or engagement of the shaft with the arm I9; As a result of this, the governor when operative does not contact or wear away any part of the switch.

The operation of the device is as follows: When the motor M is stopped, that is, when the armathe point where centrifugal action as far as the weights 24 are concerned is sufficient to overcome the inward force of the compressionsprings 42,

' the weights move outwards in the guide-ways 21 away from the tapered member 38 and compress the springs '42. As soon as the tapered member is free as a result of outward movement of the ballwtype weights, the light compression spring When the speed 4| in the socket 33 in the cap 38 shifts the switch actuating shaft 23 towards the armature shaft m and thus releases the switch so that in response to the action of gravity the holder and tube swing V downwards into their closed position. If during centrifugal force or action of the weights 24 the springs force the'weights inwards into contact with the periphery of the member 38. Because such periphery is tapered the weights set up a wedge action which overcomes the force of the spring 4| and causes the shaft 23 to move away from the armature shaft and effect opening of the switch 4. The governor serves to control the switch so that the latter is closed when the shaft m reaches a predeterminedispeed and is opened when the speed of the shaft drops below such speed. If it is desired to adjust the governor so that the latter effects closing of the switch at a higher or lower speed of the shaft m, it is only necessary to adjust the plugs 84 in the guide-ways so as to increase or decrease the force of the compression springs 42 or upon removal of the plugs to substitute lighter or heavier ball-type elements for the elements 24 or heavier or lighter compression springs for the springs 42.

The herein described circuit controlling device is extremely efficient in operation and due to the simplicity of design or construction may be manufactured at a low and reasonable cost. It has more 'or less general application although it is particularly adapted for use in a combustion system wherein a motor driven blower is used to supply air under pressure to a burner to which gaseous fuel is supplied under control of an electrically operated valve, and it is desired to control the supply of current to the valve in such manner that the valve is maintained closed except when the blower is operating to supply the desired or proper amount of air to the burner.

The invention is not to be understood as restricted to the details set forth, since these may be modified within the scope of the appended claims, without departing frogn the spirit and scope of the invention.

' Having thus described the invention, what I claim as new and desire to secure by Letters Patent is:

l. A circuit controlling device comprising in combinations. switch for the circuit, a power driven rotary element, and a governor connected to rotate with the element and embodyingv a housing with a bore in the central portion thereof and guide-ways communicating with and radiating from the bore, an axially slidable shaft in the bore adapted when slid in one direction to shift the switch into one of its positions and when shifted in the opposite direction to control the switch so that the latter is shifted into its other position and provided with a tapered member, weights movably mounted in the guide-ways and adapted when the element is driven at a certain speed to move outwards in response to centrifugal force, springs in the outer ends of the guide-ways for forcing the weights inwards when the element is driven at a lower speed and causing them to engage the member and by way of a wedging action force the member and shaft in said one direction, and means for automatically shifting the shaft in the other direction upon outward movement of the weights in the guideways.

2. A circuit controlling degce comprising in combination a switch for the circuit, a. power driven rotary element, and a governor connected to rotate with the element and embodying a housing with a bore in the central portion thereof and guide-ways communicating with and radiating from the bore, an axially slidable shaft in the bore adapted when slid in one direction to shift the switch into one of its positions and when shifted in the opposite direction to control the switch so that the latter is shifted into its other position and provided with a tapered member, weights movably mounted in the guide-ways and adapted when the element is driven at a certain to engage the member and by way of a wedging 5 action force the member and shaft in said one direction, and a compression spring, of less strength than the springs in the guide-ways extending around the shaft and adapted upon outward movement of the weights to shift the shaft 0 in said other direction.

ALBERT STADLER. 

